Piston.



c. F. PAUL, 1B.

PISTON.

APPLICATION FILED min/11.1914.

Patented Nov. 9, 1915.

nuenToz- 351 AM attozmeqafl V 1, W

prion.

CH RISTIAN F. PAUL, JR., OF PEEKSKILL, NEW YORK.

PISTON.

Specification of Letters Patent.

Patented Nov. 9,1915.

Application filed May 11, 1914. Serial No. 837,703.

T 0 all whom it may concern Be it known that I, CHRISTIAN F. PAUL,

Jr.. a citizen of the United States, residing at Peekskill, in the county of \Vestchester and State of New York, have invented certain new and useful Improvements in Pistons, of which the following is a full, clear, and exact description. r

This invention relates to piston rings, for maintaining a substantially fluid-tight joint between a piston and the cylinder in which the same works. and its chief object is to provide an improved construction of simple character which shall be simple and inexpensive to manufacture and withal thoroughly effective in use.

To this and other ends the invention consists in the novel features of construction and combinations of elements hereinafter described.

The preferred form of the invention is illustrated in the accompanying drawings, in which Figure 1 is a perspective view of the piston, removed from its cylinder. Fig. 2 is a' section on the plane of line 22, and Fig. 3 is a section on the plane of line 33 of Fig. 1. Fig. 4 is a longitudinal section of the piston and a portion of the cylinder in which it works, the section being in a plane at right angles to Fig. 1.

The piston 10 is provided on its sides with a number of superposed angularly staggered transverse slots or recesses to receive arcshaped packing-pieces or segments which are urged outwardly by suitable springs and thereby caused to bear yieldingly on thecontiguous walls of the cylinder 11. The precise number and arrangement of slots and packing-pieces used are immaterial, but in the embodiment illustrated, I provide twelve packing-pieces and of course the same number of slots to receive them. In the form shown, the uppermost slots 12, 13 are in the same plane at right angles to the axis of the piston and are diametrically opposite each other, with their inner edges substantially parallel to each other. Immediately below are similar slots 14, 15, preferably of the same size as the former, and displaced or staggered angularly 90 therefrom. Be-

low the slots 14, 15, are similar slots in vertical alinement with the slots 12, 13; while below these latter is another pair of slots, alined vertically withthe slots 14, 15. The arrangement described is repeated as often as desired, so that above or below each slot 1s a slot displaced or staggered angularly to an extent depending largely upon the angular extent ofthe slot-s themselves. If two slots in each plane are used, arranged diametrically opposite each other, each somewhat greater than 90 in extent an angular displacement of 90. between centers gives satisfactory results. The packingpieces 16 fit the slots closely, but are freely movable therein. Their curved outer edges are preferably of the same radius as the piston 10, and the pieces themselves are preferably of such width (radially) that when pressed into the slots they will substantially fill. the same.

The springs employed to press the curved packing-pieces outwardly may be of any suitable kind, but the simple leaf type shown at 17 in Figs. 2 and 3 gives as good results as any in practice. These springs are formed with a lobe or bend 18 at the center, to fit a similarly shaped or undercut notch 19 in the inner edge of the packing-piece. The ends of the springs then bear on the inner surfaces of the slots. WVhen this type of spring is used, space should be provided for the ends or wings of the springs when the packing-pieces are pressed in until their curved surfaces areflush with the surface of the piston. For this purpose the slots can be made slightly deeper than the radial width of the packing-pieces, as indicated in Figs. 2 and 3. For the best results, it .is desirable that the plane of the bottom or lower surface of each slot coincide with the plane of the upper surface of the slot or slots next below, that is: each slot should open into the slot or slots immediately below, so that each packing-piece will be in contact, at one or both ends, with the piece next above or below, as the case may be. This construction is illustrated in Fig. 1, where it is seen that each piece is in contact at its ends with the piece above or below. a

The preferred piston construction and the cylinder. areshown assembled in Fig. 4, which represents the condition when the parts are substantially worn, the packingpieces being then flush with the surface of the body of the piston. As the piston reciprocates (and in some cases rotates also) in-the cylinder, there will at first be some wear on the piston body as well as on the packing-pieces, but the latter soon take all the wear and hence soon come to fit the cyl- ,will also be observed that if the piston rotates as well as reciprocates, the cylinder and piston cannot wear into oval form, even when operated on a horizontal axis, since the rotation of the piston, in conjunction with the constant outward pressure of the packing-pieces, will distribute the Wear with substantial equality and hence keep the cylinder circular in cross section.

It is to beunderstoodethat the invention is not limited to the specific construction herein illustrated and described, but can be embodied in other forms without departure froin'its proper spirit and scope.

\Vhat I claim is:

1. The combination of a cylinder, a piston working therein and having in its sides a pluralityof axially superposed recesses off set or staggered angularly, packing pieces movably fitted in said recesses and having their outer surfaces curved in substantial conformity with the inner surface of the cylinder, and springs arranged to press the packing pieces yieldingly against the inner surface of the cylinder.

2. The combination of a cylinder, a piston working therein and having in its sides a plurality of pairs vof diametrically opposite recesses, said pairs of recesses being in different planes perpendicular to the axis of the piston and cylinder and staggered or displaced angularly with respect to each other, packing-pieces 'movably fitted in the recesses and having their outer edges curved in substantial conformity to the inner surface of the cylinder, and springs arranged to press the acking pieces against the said inner surface.

3. A piston havingin its sides a plurality of slots in a plurality of transverse planes, each slot being displaced angularly with respect to the slot or slots in the adjacent plane or planes, outwardly movable packing-pieces fitting the slots and having curved outer edges, and springs arranged to press the packing-pieces outwardly.

4. A piston having in its sides a plurality of transverse slots in a plurality of transverse planes, the slotor slots in each plane opening into, and being displaced angular-1y with respect to, theslot or slots in the ad- ]acent plane or planes, outwardly movable packing-pieces fitting the slots and having curved outer edges, and springs arranged to press the packing-pieces outwardly.

5. A piston having in its sides a plurality of pairs of diametrically opposite recesses, said pairs of recesses being in different planes perpendicular to the axis of the piston and cylinder and staggered or displaced angularly with respect to each other, outwardly movable packing pieces mounted in said slots and having curved outer edges and springs attached to the packing pieces at their inner edges and bearing on the inner faces of the slots to press the packing pieces outwardly.

6. A piston having a transverse s'lotin its side, an outwardly curved and outwardly,

CHRISTIAN -F. PAUL, JR.

Witnesses:

M. Lawson Dyan, S. S. DUNHAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Waahlngton, D. 0. 

